Creatures can also be artifacts though for a long time they did not have any Creature Types. Artifact Creatures can be affected by anything that would affect either artifacts or creatures. Currently, Artifact Creatures that are not modeled after colored creatures tend to get the creature type Golem or Construct.

301.1. A player who has priority may cast an artifact card from his or her hand during a main phase of his or her turn when the stack is empty. Casting an artifact as a spell uses the stack. (See rule 601, “Casting Spells.”)

301.2. When an artifact spell resolves, its controller puts it onto the battlefield under his or her control.

301.3. Artifact subtypes are always a single word and are listed after a long dash: “Artifact — Equipment.” Artifact subtypes are also called artifact types. Artifacts may have multiple subtypes. See rule 205.3g for the complete list of artifact types.

301.4. Artifacts have no characteristics specific to their card type. Most artifacts have no colored mana symbols in their mana costs, and are therefore colorless. However, there is no correlation between being colorless and being an artifact: artifacts may be colored, and colorless objects may be card types other than artifact.

301.5. Some artifacts have the subtype “Equipment.” An Equipment can be attached to a creature. It can’t legally be attached to an object that isn’t a creature.

301.5a The creature an Equipment is attached to is called the “equipped creature.” The Equipment is attached to, or “equips,” that creature.

301.5b An Equipment is cast and enters the battlefield just like any other artifact. An Equipment doesn’t enter the battlefield attached to a creature. The equip keyword ability attaches the Equipment to a creature you control (see rule 702.6, “Equip”). Control of the creature matters only when the equip ability is activated and when it resolves. Spells and other abilities may also attach an Equipment to a creature. If an effect attempts to attach an Equipment to an object that can’t be equipped by it, the Equipment doesn’t move.

301.5c An Equipment that’s also a creature can’t equip a creature. An Equipment that loses the subtype “Equipment” can’t equip a creature. An Equipment can’t equip itself. An Equipment that equips an illegal or nonexistent permanent becomes unattached from that permanent but remains on the battlefield. (This is a state-based action. See rule 704.) An Equipment can’t equip more than one creature. If a spell or ability would cause an Equipment to equip more than one creature, the Equipment’s controller chooses which creature it equips.

301.5d An Equipment’s controller is separate from the equipped creature’s controller; the two need not be the same. Changing control of the creature doesn’t change control of the Equipment, and vice versa. Only the Equipment’s controller can activate its abilities. However, if the Equipment grants an ability to the equipped creature (with “gains” or “has”), the equipped creature’s controller is the only one who can activate that ability.

301.5e An ability of a permanent that refers to the “equipped creature” refers to whatever creature that permanent is attached to, even if the permanent with the ability isn’t an Equipment.

301.6. Some artifacts have the subtype “Fortification.” A Fortification can be attached to a land. It can’t legally be attached to an object that isn’t a land. Fortification’s analog to the equip keyword ability is the fortify keyword ability. Rules 301.5a–e apply to Fortifications in relation to lands just as they apply to Equipment in relation to creatures, with one clarification relating to rule 301.5c: a Fortification that’s also a creature (not a land) can’t fortify a land. (See rule 702.66, “Fortify.”)